Zinc-finger nucleases (ZFNs) are engineered DNA-cutting enzymes that enable precise genome editing by creating double-strand breaks (DSBs) in specific DNA sequences. These breaks trigger cellular DNA repair mechanisms, leading to targeted mutations or gene replacements with high efficiency. ZFNs consist of DNA-binding and DNA-cleavage domains, with the cleavage domain requiring dimerization for DNA cutting. The DNA-binding domain, composed of zinc fingers, can be tailored to recognize specific DNA sequences, allowing ZFNs to target any genomic location. ZFNs have been successfully applied in various organisms, including yeast, mice, zebrafish, rats, and plants, for gene targeting and modification. The efficiency of ZFN-mediated gene targeting depends on factors such as the design of the ZFNs, the availability of donor DNA, and the cellular repair mechanisms. Homologous recombination and nonhomologous end joining are the primary repair pathways, with homologous recombination being more efficient for precise gene replacement. Despite their effectiveness, challenges remain in optimizing ZFN design and minimizing off-target effects. Recent advancements include the development of improved ZFN architectures that enhance specificity and reduce toxicity. ZFNs have shown promise in human gene therapy, particularly in clinical trials targeting diseases such as HIV-1 resistance. However, further research is needed to refine ZFN technology and expand its applications in diverse organisms and biological contexts. The future of ZFN-based gene targeting appears bright, with ongoing efforts to improve efficiency, specificity, and safety for a wide range of genetic applications.Zinc-finger nucleases (ZFNs) are engineered DNA-cutting enzymes that enable precise genome editing by creating double-strand breaks (DSBs) in specific DNA sequences. These breaks trigger cellular DNA repair mechanisms, leading to targeted mutations or gene replacements with high efficiency. ZFNs consist of DNA-binding and DNA-cleavage domains, with the cleavage domain requiring dimerization for DNA cutting. The DNA-binding domain, composed of zinc fingers, can be tailored to recognize specific DNA sequences, allowing ZFNs to target any genomic location. ZFNs have been successfully applied in various organisms, including yeast, mice, zebrafish, rats, and plants, for gene targeting and modification. The efficiency of ZFN-mediated gene targeting depends on factors such as the design of the ZFNs, the availability of donor DNA, and the cellular repair mechanisms. Homologous recombination and nonhomologous end joining are the primary repair pathways, with homologous recombination being more efficient for precise gene replacement. Despite their effectiveness, challenges remain in optimizing ZFN design and minimizing off-target effects. Recent advancements include the development of improved ZFN architectures that enhance specificity and reduce toxicity. ZFNs have shown promise in human gene therapy, particularly in clinical trials targeting diseases such as HIV-1 resistance. However, further research is needed to refine ZFN technology and expand its applications in diverse organisms and biological contexts. The future of ZFN-based gene targeting appears bright, with ongoing efforts to improve efficiency, specificity, and safety for a wide range of genetic applications.